How to Have Children in Fields of Mistria
The Mystical Feather
Children are optional and only come up once you're married. A while into married life, a cutscene gives you a Mystical Feather. Using it opens a family planning conversation whenever you feel ready.
The Parent Path
Starting a family is tied to the Mystical Feather and dreams of the Great Bird. It's an optional path — you can remain child-free if you prefer, with no gameplay penalty.
Make sure you've completed marriage first — the children system only becomes available after you settle into married life.